Broadband-excited and efficient blue/green/red-emitting Ba2Y5B5O17:Ce3+, Tb3+, Eu3+ phosphors using Tb3+-bridged Ce3+-Eu3+ energy transfer

A series of broadband-excited and color-tunable Ba2Y5B5O17: Ce3+, Tb3+, Eu3+ phosphors were synthesized using Ce3+-Th3+-Eu3+ energy transfer and their luminescent properties have been comprehensively studied. The Tb3+ ions act as an energy transfer bridge between Ce3+-Eu3+ ion pairs, which can alleviate metal mediated charge transfer (MMCT) quenching. Therefore, the Eu3+ linear red emission was efficiently sensitized by Ce3+ broad excitation band through a Tb3+ bridge. The emitting color of Ba2Y5B5O17: Ce3+ Tb3+ Tb3+, Eu3+ phosphors could be tuned from blue through green and finally to red with increasing Tb3+Eu3+ content. By analyzing the variation of the emission intensity and decay lifetime of the sensitizer, it was found that the energy-transfer mechanism of Ce3+-Tb3+ and Tb3+-Eu3+ is dipole-quadrupole and exchange interactions, respectively. The phosphors exhibit high-efficient and blue-green-red color-tunable emission (QE > 40 %) and good thermal stability against temperature quenching (T-50 > 473 K).